Testing of the crease resistance of textile fabrics



a 1 m 0a. 27, 1959 ALD N 2,909,921 5 5 :11?" TESTING OF THE GREASE RESISTANCE OF TEXTILE FABRICS f Filed Dec. 1'7, 1956 3 Sheets-Sheet 1 afn y Oct. 27, 1959 w. K. DONALDSON 2,909,921

ms'rmc OF THE cams: RESISTANCE 01-" TEXTILE FABRICS Filed Dec. 17, 1956 s Sheets-Sheet 2 Attorney;

0d. 27, 1959 w DQNALDSQN 2,909,921

TESTING 0F THE GREASE RESISTANCE 0F TEXTILE FABRICS Filed Dec. 1'7. 1956 3 Sheets-Sheet 3 United States Patent TESTING OF THE CREASE RESISTANCE 0F TEXTILE FABRICS 'William Kenneth Donaldson, Manchester, England, as-

Application December 17, 1956, Serial No. 628,902

Claims priority, application Great Britain December 19, 1955 3 Claims. (Cl. 73-100) The present invention relates to methods and apparatus for testing the property of textile fabrics recovering from creasing when wet or dry and particularly of drying in a smooth state after laundry washing and without ironing whereby information can be obtained and used to improve and control the manufacture of crease resisting textile fabrics. Hereinafter the said property will be referred to as crease-resistance.

The method of testing the crease resistance of textile fabrics according to the present invention comprises forming two parallel oppositely directed creases in a specimen of the fabric, laying the specimen in open form on a flat surface and optically measuring the inclination to said flat surface of the fabric between the creases.

More precisely the method of the invention comprises folding a specimen of the fabric in S or Z form and applying pressure to the folds to form two parallel oppositely directed creases therein, withdrawing the pressure from the specimen, laying it in open form on a flat surface and optically measuring the inclination to the flat surface of the plane containing the creases.

The measuring of said inclination is preferably carried out with the aid of a substantially linear light source disposed substantially parallel to the creases, the position of the light source relative to the plane containing the creases being adjusted to bring it into alignment with said plane, so that when moved in one direction slightly out of alignment it will throw a shadow on one of the creases. In other words the light source is adjusted until the upwardly convex crease just prevents rays of light substantially parallel with the plane of the creases from illuminating the upwardly concave crease.

The light source need not necessarily be a linear light source but may be a light source disposed substantially in a plane so that when viewed from the edge of the plane it would appear linear and so that that part of the light source can be adjusted so that its plane can be brought into coincidence or substantially into coincidence with the plane of the creases. Thus the light source could be in the form of an are lying in a plane or it could be of linear form inclined to the creases but capable of being adjusted so that it can be brought into the plane of the creases. Any suitable form of light source may be employed. For example the light source may be a filament or an image in a lens.

In carrying out the method of the present invention for the purpose of measuring the property of a textile fabric drying in a smooth state after washing and without ironing a specimen of the textile fabric may be creased by folding in a wet condition and then dried in an unfolded condition and then laid upon a flat surface in order to measure the inclination thereto of the plane of the fabric between the creases. Thus the method may include the steps of wetting or washing the specimen, then mangling it, then creasing it, then drying it and then performing the aforesaid measuring step.

The method may include the step of creasing a specimen of a fabric by holding it in a folded condition for a prescribed period of time with a prescribed degree of pressure applied to the folds. The prescribed pressure may be applied by placing upon the folded specimen a flat plate of given length and width and applying to the flat plate a load of given value.

The aforesaid measuring operation is preferably carried out by holding the specimen on the flat surface under slight tension in the longitudinal direction of the creases and moving the light source until the tip of the crease which is convex towards the light source just intercepts the rays of light falling on the other crease.

An apparatus for use in folding the specimen in a standard manner may comprise a platform on which a fabric specimen can be laid, guide means at opposite sides of said platform fixed relatively thereto and thin fold plates at opposite sides of the platform guided by said guide means and movable away from and towards the platform to bring their adjacent edges to prescribed positions above the platform in close interfacial relationship with one another and with the platform with one plate lying above and overlapping the other to a prescribed extent. Soid fold plates may be arranged at levels one just above the platform and the other just above said one plate so that they may be moved into overlapping positions above the platform by simple linear movement or alternatively said other plate may be arranged for a combined upward and downward and transverse movement relatively to the platform to bring it into a position above and overlapping said one plate after said one plate has been moved into position with its edge overlying the platform.

The invention is further described by way of example with reference to the accompanying drawings in which:

Fig. 1 is a diagrammatic view illustrating the method of the present invention,

Fig. 2 is a side view,

Fig. 3 is a corresponding plan view and Fig. 4 is an end sectional view taken on the line IVIV of Fig. 3 illustrating one suitable form of folding apparatus, and

Fig. 5 is a sectional side view, Fig. 6 is a plan view and Fig. 7 is a sectional end view taken on the line VIIVII of Fig. 6 illustrating one suitable form of optical measuring apparatus.

Fig. l is a diagrammatic illustration of one mode of carrying out the method of the present invention; the various elements shown therein are not drawn to the same scale.

An oblong specimen 1 of textile fabric to be tested in wetted in a liquid bath 2 and is then mangled by rollers 3. The specimen 1 is then placed on a platform 4 and a thin fold plate 5 having a straight edge 6 is slid into a position above the platform 4. The specimen 1 is then folded around the edge 6 of the plate 5 and a second fold plate 8 at the righthand side of the platform 4 is then moved to the left to bring it to a position where its left hand edge, which is parallel to the edge 6 of the plate 5, is approximately above the edge of the plate 5. Plate 8 is then moved down and a little further to the left to press lightly on the fabric. The fabric specimen 1 is then folded around the edge of the plate 8 to bring the sample into a condition in which it is oppositely folded in S or Z form along the margins of a narrow band 9 the fabric.

A pressing plate 10 preferably of glass is placed upon the folds and plates 5 and 8 are then withdrawn from the folded fabric whilst the fabric is held in its folded condition. A weight 11 is then placed upon the glass plate 10 to apply a prescribed degree of pressure to the folds for a prescribed period of time during which the fabric and the parts of the creasing apparatus in contact therewith are preferably kept at a prescribed temperature, e.g. 40 C.

Instead of using a weight 11 the creasing pressure may be applied for example by means of a spring or through a weight acting through a lever or system of levers to give a higher pressure for a given applied weight. The specimen is thus held under pressure for a prescribed period of time, removed from the folding device and is then hung in an open condition in a heated drier chamber 12 at a prescribed temperature and for a prescribed time. The recovery from creasing may be assisted before and/or during and/ or after the drying of the specimen for example by shaking e.g. by suspending it from a vibrating arm (as diagrammatically indicated at 19 in Fig. 1) for a defined period of time. Alternatively the recovery from creasing may be assisted by passing the specimen in open form around a roller or between rollers or by placing it beneath a weight for a given time.

The dried specimen indicated by the reference numeral 101 in Fig. 1 is then removed from the chamber 12 and placed upon a flat surface 13. The inclination of the narrow band 9 of the sample to the flat surface 13 is measured with the aid of a lamp 14 within a lamp housing 15 the lamp having a substantially linear filament substantially parallel to the creases. The lamp assembly can be moved in an arcuate path about the crease 17 which is concave towards the light source so that it can be brought from say a central position shown in dotted lines in Fig. 1 to a position where the tip of the crease 18 which is upwardly convex begins to throw a shadow at the concave crease 17.

The angle A indicated in Fig. 1 alfords a measure of the crease resistance of the fabric, the crease resistance being the greater as the magnitude of the angle A is the less.

The folding apparatus which is shown fragmentarily and somewhat diagrammatically in Fig. 1 is more completely illustrated in Figs. 2, 3 and 4 which should be read in conjunction with Fig. 1 which shows certain of the parts to a larger scale.

The folding apparatus comprises a base 20 with a platform 4 on which the sample is placed. The lefthand fold plate is supported by a carrier plate 16 having lugs 21, 22 therebeneath which are slidable in guides 23, 24 in the base 20. The level of the plate 5 is slightly higher than that of the platform 4. Plate 5 is moved with the aid of a handle 25 projecting upwardly from its carrier plate 16.

The righthand fold plate 8 is secured to the lefthand side of a carrier plate 26 which has two pairs of bearing lugs 27 therebenath (Figs. 1 and 4) having bearing openings therein to receive a spindle 28 which is connected through cranks 29 with spindles 30 which are eccentric to the spindle 28 and which are in turn connected to operating cranks 31 at the ends thereof. The operating cranks 31 of the two spindles 28 are interconnected by connecting rods 32 and are operated by a lever 33 which is locked to the righthand spindle 28 as viewed in Fig. 3. Thus appropriate angular movement of the lever 33 will cause the fold plate 8 to be moved through an arcuate path downwardly to the left to bring it to the position shown in Fig. 2.

For the purpose of limiting the movement of the plate 5 to the right threaded bolts 34 are screwed into the ends of the lugs 21 of the plate 5 for engagement with the righthand ends of the guides 23. The bolts 34 can be locked by means of lock nuts.

The ends of the eccentric spindles 30 engage in bearing openings in the opposite walls of a frame 35 which is slidable in guides 36 and whose movement to the left is limited by adjustable cams 37 on the base 20. The extent to which the fold plate 8' can overlap the fold plate 5 is thus limited by the cams 37.

After the specimen has been folded with the aid of the fold plates 5 and 8 the pressing plate is placed upon the folds and the fold plates 5 and 8 are withdrawn. Pressure is applied to the pressing plate 10 by a weight 11 secured to pivoted arms 38 by means of which it can be moved from an inoperative position shown in broken lines in Fig. 2 to an operative position shown in full lines. To ensure that the plate 10 is maintained parallel to the platform 4 for the purpose of applying equal pressure to the two folds a pair of adjustable button-headed screws 39 are provided on the lower face of the weight 11. The pivoting of the arms 38 of the weight 11 about a fixed pivot predetermines the position of the weight in relation to the platform 4 and appropriate adjustment of the screws 39 enables the plate 10 to be maintained parallel with the platform 4 and so to apply substantially equal pressure to the folds in the specimen.

The measuring apparatus illustrated in Figs. 5, 6 and 7 comprises a base 40 which supports a casing 41 of which the upper part is semi-cylindrical. The casing 41 has a viewing aperture 42 therein and a larger opening 43 through which the specimen can be passed. A platform 44 preferably of glass is mounted within the casing and is provided at its lefthand edge with a clamp 45 to hold one end of a fabric specimen the other end of which is held between rollers 46, 47. Roller 46 has a weight 48 attached thereto to apply a mild torque to the roller 46 and thus slight tension to the fabric specimen. Roller 47 is supported between pivoted arms 49 which allow it to rest upon the roller 46 and to be readily withdrawn therefrom as indicated in broken lines in Fig. 5.

A lamp housing 50 is mounted on a cranked arm 51 which is pivoted on a rotatable spindle 52 and can be angularly displaced by means of a knurled knob 53 to enable the lamp housing to be moved in an arcuate path about the axis of the spindle 52. The angular position of the lamp housing 50 can be determined by means of a graduated scale 54 on the knob 53 and a fixed pointer 55. Fine adjustment of the lamp housing can be made by turning a knob 56 or 57 mounted on a spindle 58 which is journalled in the end walls of the casing 41 and which has a friction wheel 59 fixed thereto and engaging with the knurled knob 53. The lamp housing has a slit 60 therein parallel to the longitudinal axis of the platform 44. A lamp 61 Within the lamp housing 50 has a substantially linear filament disposed substantially parallel to the shaft 52 and to the slit 60.

The fabric specimen should be arranged on the platform 44 so that the concave crease 17 (Fig. 1) is substantially in line with the axis of the spindle 52. With the specimen in position on the platform 44 the inclination to the platform 44 of the band 9 of the specimen (Fig. 1) can be determined by viewing the specimen through the viewing aperture 42 and adjusting the angular position of the lamp housing 50 until a shadow of the convex crease 18 begins to darken the band 9 of the specimen between the folds.

In carrying out the method of the present invention it is advantageous to place a long narrow plate on the fabric parallel to the creases a short distance to the left of the concave crease 17 as viewed in Fig. 1 so as to help to ensure that that part ofthe specimen is flat when the measuring step is carried out. It is advantageous to carry out a number of measuring steps on each specimen at different parts of the length of each crease and, after a first set of measuring steps have been performed, to turn the fabric over and carry out a number of measuring steps in relation to the opposite face of the crease. The inclination of the fabric between the creases can then be taken as an average of say ten measurements.

The position of the scale 54 and pointer 55 relatively to the viewing aperture 42 should be such that the scale cannot readily be read without movement of the head of the operator from a position appropriate for viewing the specimen through the aperture 42. This is desirable in order to avoid the possibility that the operator may be influenced by the scale in deciding the point at which a shadow is cast by the convex crease on the concave crease.

I claim:

1. A method of test-ing the crease resistance of a textile fabric which comprises folding a specimen of the fabric in S or 2 form and applying a given pressure to the folds for a predetermined period of time to form two parallel oppositely directed creases therein, withdrawing the pressure from the specimen, laying it in open form on a fiat surface and optically measuring the inclination to the flat surface of the plane containing the creases.

2. A method of testing the crease resistance of a textile fabric which comprises wetting a specimen of the fabric, folding the specimen in S or Z form and applying a prescribed pressure for a prescribed period of time to the folds of the specimen to form two parallel oppositely directed adjacent creases therein, withdrawing the pressure from the specimen, subjecting the specimen to a drying operation and then laying it in open form on a flat surface under slight tension in the direction of the creases and optically measuring the inclination to the flat surface of the plane containing the creases.

3. A method of comparing the crease resistance of textile fabrics which comprises wetting specimens of the fabrics, folding each specimen in S or Z form and applying a prescribed pressure for a prescribed period of time to the folds of each specimen to form two parallel oppositely directed adjacent creases therein, withdrawing the pressure from each specimen, subjecting each specimen to a drying operation and then laying it in open form on a fiat surface under slight tension in the direction of the creases and optically measuring the inclination to the flat surface of the plane containing the creases.

References Cited in the file of this patent UNITED STATES PATENTS 1,930,077 Bentley Oct. 10, 1933 1,937,820 Howard Dec. 5, 1933 2,219,701 Remington Oct. 29, 1940 2,247,211 Salk June 24, 1941 2,342,273 Hayward Feb. 22, 1944 2,613,019 Silverman Oct. 7, 1952 2,708,059 Petzal et a1. May 10, 1955 

